Raymond : Thk Chazy Formation and its Fauna. 50!) 



sandstone with thin partings of dark limestone, which represent the 

 lowest division of the Chazy. The coarse sandstones at the base of 

 the formation in this region point to very shallow water and shore 

 conditions in the Ottawa Valley, and a probable interval of erosion 

 between the end of Beekmantown time and the deposition of the 

 strata of Chazy age. As will be seen later, the fauna also indicates a 

 break between the two formations. 



The Chazy formation occurs in a narrow belt extending along the 

 north and south sides of the Ottawa River from Hawkesbury west to 

 Arnprior and is again exposed south of Ottawa and eastward to Corn- 

 wall, where it turns northward and connects with the northern belt at 

 Hawkesbury. This belt of Chazy does not connect with the Chazy of 

 the Champlain region. West of Arnprior there are two localities in 

 which there are outcrops of Chazy rocks. One is at Allumette Island, 

 north of Pembroke, and the other ten or fifteen miles south of this 

 and west of Renfrew. In the Ottawa region the Chazy is usually under- 

 lain by the Beekmantown and overlain by the Lowville limestone. The 

 Beekmantown is, however, very different lithologically and faunally 

 from that in the Champlain Valley. The contact with the overlying 

 Lowville limestone is not well shown, but the Upper Chazy limestone 

 seems to grade into the buff dolomite of the Lowville formation with- 

 out a break. 



The Mingan Islands. 



The best account of the Chazy at the Mingan Islands is given by 

 Sir William Logan in the Geology of Canada, 1863, page 134. The 

 following quotations will serve to explain the occurrence there. 



" The lowest part seen of the deposit occurs in the bay above Clear 

 Water Point and the following is the section of the strata in ascending 

 order : 



"Reddish cream-colored, compact limestone with conchoidal frac- 

 ture ; weathering pale yellow. 1 foot. 



"Greenish and blackish brown shale. i foot. 



"Reddish cream-colored limestone, like Xo. 1, in beds i inch to 2 

 inches to a foot, interstratified with greenish shale in l)eds of about the 

 same thickness. 



"Greenish shale with Camarotccchia orieiitalis (variety of Caniaro- 

 ta'chia plena) in great abundance. 3 feet. 



" Granular limestone with false bedding, holding comminuted frag- 



